人工调控对禾草混播草地群落特征的影响

Artificial Control Impact on Community Character of Gramineous Mixed Grassland

在三江源区的"黑土滩"退化草地上,以当地野生驯化牧草,垂穗披碱草(Elymus nutans Griseb)、青海草地早熟禾(Poa pratensis L. cv. Qinghai)、青海中华羊茅(Festuca sinensis Keng cv. Qinghai)、青海冷地早熟禾(Poa crymophila Keng cv. Qinghai)、碱茅(Puccinellia distans(L.)Prarl)和西北羊茅(Festuca kryloviana Reverd.)为种源,设人工调控和对照2组处理,每组处理6个混播组合,探索不同草种组合和调控措施下人工群落的生产力与稳定性。2006-2008年试验表明:人工调控各组合群落的高度、盖度和植物量均显著高于对照,组合群落中禾草植物量第2、3年分别比相应对照组合高1倍和2倍以上,群落结构和稳定性显著高于对照;不同品种搭配下,混播组合群落的高度、盖度和植物量高于垂穗披碱草单播群落,第3年的群落植物量和禾草植物量比例均高于单播群落,随着组合草种增加,混播群落对环境条件的适应性增强,群落中禾草与杂类草的竞争力显著增强,群落稳定性提高;综合比较,初步确定以垂穗披碱草+青海草地早熟禾+青海中华羊茅+青海冷地早熟禾+碱茅+西北羊茅和垂穗披碱草+青海草地早熟禾+青海中华羊茅+青海冷地早熟禾为三江源区"黑土滩"退化草地建植混播人工草地的合理组合。同时,合理的草地管理有利于提高人工草地的生产力,延长草地利用年限。

In order to support the restoration and rehabilitation of degraded grassland in Black Soil Bottomland of Three-river Source Region,the productivity and stability of artificial grassland with different species composition and control measures were explored in three years based on the local acclimated wild grasses（Elymus nutans Griseb.,Poa pratensis L.cv.Qinghai,Festuca sinensis Keng cv.Qinghai,Poa crymophila Keng cv.Qinghai,Puccinellia distans（L.） Prarl.,and Festuca kryloviana Reverd.） by two treatment sets of artificial control and CK with 6 mixed species combinations within each set.The result show that the height,coverage,and biomass of mixed combination communities under artificial control measures were all higher than those in CK,grass biomass of mixed species communities were 1 and 2 times of the corresponding CK in second and third year after rehabilitation,respectively,and community composition and stability were higher significantly in mixed species communities under artificial control measures than those under corresponding CK.In different species combination communities,the height,cover and biomass of the mixed species communities were significantly higher than those in the single species communities.The biomasses of the mixed species communities were higher than the single seed community in the third year.With the increasing of species in combination,the community adaptation to the environment,the competitiveness of the grasses to forbs,and the community stability were also increased.In summary,E.nutans＋P.pratensis＋F.sinensis＋P.crymophila＋Pu.Distans＋F.kryloviana and E.nutans＋P.pratensis＋F.sinensis＋P.crymophila were two reasonable mixed species combinations for the restoration and rehabilitation of degraded grasslands,and rational grassland management would improve the productivity and prolong the utilization time of artificial grassland.